Company · Ownership research

Sionna Therapeutics, Inc. SION

CIK 0002036042 · CUSIP 829401108

Insider trading Initial holdings Institutional holders

Quarter-end disclosures, not live holdings.

This page lists the top 20 of 122 rows by value; the complete set is available through the API.

Some filings reported values in thousands; those figures were scaled ×1,000 to dollars.

Top 20 institutions

Weight means this stock's share of the manager's own portfolio.

By reported value

#	Manager	Value	Manager weight	Change vs prior	Source
01	RA CAPITAL MANAGEMENT, L.P. CIK 1346824 · View history	$397.09M 9,905,045 shares	4.21%	0(0.00%)Unchanged	SEC filing ↗ May 15, 2026	▾
02	TPG GP A, LLC CIK 1903793 · View history	$260.38M 6,494,962 shares	7.08%	-250.00K(-3.70%)Reduced	SEC filing ↗ May 15, 2026	▾
03	ORBIMED ADVISORS LLC CIK 1055951 · View history	$141.55M 3,530,702 shares	3.10%	-30.95K(-0.90%)Reduced	SEC filing ↗ May 15, 2026	▾
04	VIKING GLOBAL INVESTORS LP CIK 1103804 · View history	$128.09M 3,195,181 shares	0.36%	0(0.00%)Unchanged	SEC filing ↗ May 15, 2026	▾
05	Atlas Venture Life Science Advisors, LLC CIK 1917529 · View history	$120.09M 2,995,602 shares	15.20%	0(0.00%)Unchanged	SEC filing ↗ May 14, 2026	▾
06	ENAVATE SCIENCES GP, LLC CIK 1953107 · View history	$99.34M 2,478,030 shares	28.26%	0(0.00%)Unchanged	SEC filing ↗ May 15, 2026	▾
07	JENNISON ASSOCIATES LLC CIK 53417 · View history	$58.18M 1,451,220 shares	0.04%	+335.94K(+30.10%)Added	SEC filing ↗ May 6, 2026	▾
08	JPMORGAN CHASE & CO CIK 19617 · Amended · View history	$53.71M 1,465,014 shares	0.00%	+233.19K(+18.90%)Added	SEC filing ↗ May 13, 2026	▾
09	BlackRock, Inc. CIK 2012383 · View history	$51.95M 1,295,867 shares	0.00%	+4.27K(+0.30%)Added	SEC filing ↗ May 13, 2026	▾
10	CITADEL ADVISORS LLC CIK 1423053 · View history	$46.78M 1,166,931 shares	0.03%	+79.61K(+7.30%)Added	SEC filing ↗ May 15, 2026	▾
11	VANGUARD CAPITAL MANAGEMENT LLC CIK 2100119 · Amended · View history	$41.27M 1,029,497 shares	0.00%	—	SEC filing ↗ May 15, 2026	▾
12	DEERFIELD MANAGEMENT COMPANY, L.P. (SERIES C) CIK 1009258 · View history	$38.91M 970,590 shares	0.46%	0(0.00%)Unchanged	SEC filing ↗ May 15, 2026	▾
13	PRICE T ROWE ASSOCIATES INC /MD/ CIK 80255 · View history	$30.32M 756,376 shares	0.00%	-75.00K(-9.00%)Reduced	SEC filing ↗ May 15, 2026	▾
14	STATE STREET CORP CIK 93751 · View history	$30.32M 756,227 shares	0.00%	+62.83K(+9.10%)Added	SEC filing ↗ May 15, 2026	▾
15	PERCEPTIVE ADVISORS LLC CIK 1224962 · Amended · View history	$26.40M 658,439 shares	0.52%	-520.66K(-44.20%)Reduced	SEC filing ↗ May 29, 2026	▾
16	EVENTIDE ASSET MANAGEMENT, LLC CIK 1442891 · View history	$25.88M 645,530 shares	0.43%	+6.49K(+1.00%)Added	SEC filing ↗ May 15, 2026	▾
17	Aberdeen Group plc CIK 1716774 · View history	$22.62M 564,175 shares	0.04%	-275.79K(-32.80%)Reduced	SEC filing ↗ Apr 29, 2026	▾
18	BAKER BROS. ADVISORS LP CIK 1263508 · View history	$16.04M 400,000 shares	0.09%	0(0.00%)Unchanged	SEC filing ↗ May 15, 2026	▾
19	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$15.63M 389,872 shares	0.00%	+9.83K(+2.60%)Added	SEC filing ↗ May 15, 2026	▾
20	Siren, L.L.C. CIK 2005245 · View history	$12.03M 300,000 shares	0.33%	0(0.00%)Unchanged	SEC filing ↗ May 14, 2026	▾

Showing 20 / 122 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

122

Cancelled or null records excluded

Disclosed shares

45,407,312

Not deduplicated across managers

Disclosed value

$1.82B

Not market cap or free float

Reporting institutions by quarter

Counts also change with data coverage and reporting entities; they do not measure net buying. Distinct managers with a live stock row in this CUSIP; totals may include overlapping filings and are not a share of the company.

Sionna Therapeutics, Inc. · Q1 2026

Explore all 122 reporting institutions.

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Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.